A laboratory makes use of several materials and consumables in the course of its routine operations. Such materials can be classified into different categories such as
- Routine supplies and consumables
- Standard reference materials
- Samples under proficiency test studies
The number of items used in the laboratory is vast and depends to a large extent on the analysis objectives of the laboratory. Routine supplies and consumables cover laboratory chemicals and reagents for general use, indicators, gases common glassware items, chromatographic columns, septas, vials, etc. The list also includes glassware, thermometers, pH meters, magnetic shakers, etc. Such items should be procured from reputed vendors and should be of approved quality but these do not fall into the critical supplies category which needs special attention and controls.
The present article focuses on procurement, storage and management of the critical supplies.
Standard Reference Materials
Standard reference materials and reagents of high purity are essential requirements in any laboratory as these assure high reliability of results. Sub-standard reagents and standard reference materials which do not have traceability to national or international standard bodies will undoubtedly yield unreliable results. The management of such materials involves active involvement of all categories of laboratory employees.
The purchase manager identifies the vendor from the approved vendor list who can supply the quality of items required by the quality assurance manager. On material receipt the quality manager checks the condition of packaging, material description, freedom from moulds growth or extra constitutional impurities and its chemical analysis report inn thy laboratory before giving his approval of acceptance. The material is accepted by the store manager and issued to the laboratory. In case of any observed abnormalities the material is rejected and returned to the supplier citing the reasons for rejection. The user has to ensure that the material is used before its expiry date. A responsible user has to keep maintain a user log and discard the expired items as per the laboratory standard procedures.
Samples Under Proficiency Testing
Samples received for proficiency testing are crucial for the reputation of a laboratory and contribute to its high revenues. It is for this reason that such samples need careful attention and handling from receipt till analysis.
On receipt the samples should be checked for correctness of labeling details and proper sealing. The sample needs to be stored under its prescribed environmental conditions. It is equally important for the analyst to ensure that the instruments including weighing balances are calibrated and calibration records are maintained. The sample is divided among three different validated analysts and the mean of analysis results are reported.
Volumetric glassware is often taken for granted but regular calibration is a must when the results of highest degree of accuracy and reliability are required. The volumetric glassware and other apparatus used should be of highest quality and certificate of calibration should be available from the supplier.
It can be summarized that apart from systematic analysis there is a need for contamination free storage under right environmental controls, time between sample receipt and collection till analysis is kept minimum and proper conditions are maintained when sample needs to be transported from collection site to the testing laboratory. Samples requiring storage at low temperatures should be allowed to attain ambient laboratory temperature before starting analysis.
Finally the laboratory staff including purchase, stores and analysts should be made to undergo scheduled training programs to update their knowledge and skills necessary for proper management of critical laboratory supplies and samples.